This map shows Superfund sites on the National Priorities List, including those the EPA says are inaccessible from the ground. The animation shows flights of the EPA's ASPECT aircraft, which can measure chemical pollution from the air, as detected by the flight-tracking site, Flightradar24. This may be an incomplete record of flights by the plane, which has been monitoring Superfund sites and the Arkema chemical plant that caught fire on Thursday and Friday.

Tropical storm Harvey damaged at least 13 dump sites for thousands of tons of industrial waste, but flooding has prevented the EPA from inspecting damages in all but two sites, the agency said Saturday.

This was the agency's first major update on the status of the federally managed "Superfund" sites, and came shortly after the AP reported that seven sites near Houston had been flooded.

It could take months to assess the impact of the storm on these sites, said Ivan Rusyn, director of the Superfund Research Center at Texas A&M University, funded by the National Institute of Environmental Health Sciences.

"I understand frustration that people have — they want to see federal employees and state employees giving them information right away," Rusyn told BuzzFeed News. Today's emergency response systems prioritize getting people out of the water, and assessing environmental impacts after that. Part of the goal at the Superfund Research Center is to develop better responses to natural disasters at these sites.

Texas hosts 66 Superfund sites, chosen for monitoring by the EPA because hazardous chemicals stored there pose a risk to human health. The agency said that 41 were in zones hit by Harvey, and that agency staff had used aerial surveillance to determine that at least 13 have been damaged or flooded in some way.

The agency confirmed the AP’s report that two sites in Corpus Christi were the only Superfund sites it was able to access.

Among the underwater sites near Houston, as reported by the AP, were: the San Jacinto River Waste Pits in Harris County, which received sludge from paper mills for years, leading to pollutants like dioxins contaminating the nearby soil, water, and fish. The Texas Parks and Wildlife Department has an active advisory on consuming fish and crab caught in that region of the river. The waste is stored in 3.5 acres of partially submerged dumps — the EPA said that a "temporary armored cap" had been installed to prevent the waste from flowing away.

Over the years, Highland Acid Pits, another Harris Country site, collected an unknown amount of industrial waste, including sulfuric acid from oil and gas refining, leaching hazardous chemicals into the soil and groundwater. The EPA has extracted 33,000 tons of sludge from that area, but continues to monitor it. The AP reported that this site had also been flooded.

In the second of two responses to the AP report, the agency took aim at AP reporter Michael Biesecker, claiming that his report "from the comfort of Washington" was "incredibly misleading," and mentioning a correction in a previous story Biesecker had written, regarding Administrator Scott Pruitt's schedule.

AP executive editor Sally Buzbee said in a statement to BuzzFeed News that the AP report was based on visits to Superfund sites in and around Houston. "We object to the EPA's attempts to discredit that reporting by suggesting it was completed solely from 'the comforts of Washington' and stand by the work of both journalists who jointly reported and wrote the story," she said.

No Superfund site has ever seen this kind of flooding before, so experts don't know what kind of damage to expect.

"We’ve never seen precipitation to this level at any Superfund site," Jennifer Horney, an associate professor of epidemiology at Texas A&M University told BuzzFeed News. "The main problem is that we don’t know what to expect."

On Friday, Horney led a team to collect soil and water samples from the Manchester neighborhood, one of those that had been affected by flooding. She explained that many Houston communities are already exposed to emissions from chemical factories and refineries in the city's petro-chemical complex. Added to that, there is now the threat of hazardous chemicals flowing out of storage sites.

"We don’t have any precedent to figuring out what the cumulative affect is going to be on someone’s health," Horney said. "They're not going to get cancer tomorrow — they may get asthma in three months."

If you've been impacted by the storm in Texas or have a tip about rescue, relief, government, or aid efforts, call the BuzzFeed News tipline at(646) 589-8598. Find us on Signal, email, SecureDrop, and morehere.

UPDATE

Sep. 04, 2017, at 00:13 AM

This article was updated to include comment from AP executive editor Sally Buzbee.